package com.atwulidun.facade09;

public class Stereo {
    // 饿汉式
    private static final Stereo instance = new Stereo();

    public static Stereo getInstance() {
        return instance;
    }

    public static void on() {
        System.out.println("Stereo on");
    }

    public static void off() {
        System.out.println("Stereo off");
    }

    public static void down() {
        System.out.println("Stereo down");
    }

    public static void up() {
        System.out.println("Stereo up");
    }

}
